1.A large vessel, cistern, or tub, especially one used for holding liquors in an immature state, chemical preparations for dyeing, or for tanning, or for tanning leather, or the like. "Let him produce his vats and tubs, in opposition to heaps of arms and standards."
2.A measure for liquids, and also a dry measure; especially, a liquid measure in Belgium and Holland, corresponding to the hectoliter of the metric system, which contains 22.01 imperial gallons, or 26.4 standard gallons in the United States. Note: The old Dutch grain vat averaged 0.762 Winchester bushel. The old London coal vat contained 9 bushels. The solid-measurement vat of Amsterdam contains 40 cubic feet; the wine vat, 241.57 imperial gallons, and the vat for olive oil, 225.45 imperial gallons.
4.(R. C. Ch.) A vessel for holding holy water.
...